Re: Perl allows you to change the definition of false to make it true. (And vice versa.)

in reply to Perl allows you to change the definition of false to make it true. (And vice versa.)

This should please the comp.lang.c old timers:

use strict;
use warnings;
use 5.010;

BEGIN {
    &Internals::SvREADONLY(\undef, 0);
    ${\undef} = "Demons are coming out of my nose!";
};
[download]

I wonder if you can redefine other read-only values? I could not get the following to work.

BEGIN {
    &Internals::SvREADONLY(\'blue', 0);
    ${\'blue'} = 'turtle';
    
    &Internals::SvREADONLY(\5, 0);
    ${\5} = 5.000000000001;
    
};
[download]

(I have no idea why you would want to do this apart from JAPH or intentional sabotage)

Comment on Re: Perl allows you to change the definition of false to make it true. (And vice versa.) Select or Download Code

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Re^2: Perl allows you to change the definition of false to make it true. (And vice versa.) by tobyink (Canon) on Dec 14, 2012 at 15:14 UTC
AFAIK, only true, false and undef. I thought perhaps "0 but true" might work (as that has special handling - it doesn't warn if used in numeric context) but no joy. `perl -E'sub Monkey::do{say$_,for@_,do{($monkey=[caller(0)]->[3])=~s{::}{ }and$monkey}}"Monkey say"->Monkey::do'`	[reply]

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